Information processing method and information processing system

ABSTRACT

Predetermined hologram images  7   a   , 7   b  formed by three-dimensionally arranging a plurality of data items constituting data group information are read out from hologram devices  6   a   , 6   b , and an image correlation calculation between the hologram images  7   a   , 7   b  is carried out by a Fourier transform optical system constituted by Fourier transform lenses  8, 13  and an optical address type SLM  9 , whereby a correlation value of data groups is detected by a photodetector  14.

TECHNICAL FIELD

The present invention relates to an information processing system whichprocesses data of a data group comprising a plurality of informationitems in parallel; and, in particular, to an information processingmethod and information processing system which carry out data processingbetween group information items of data groups each including a numberof information items.

BACKGROUND ART

In the present age known as information-oriented society, various kindsof data are stored, and a variety of databases are constructed. Suchdatabases are meaningless if they are simply stored. The added value andutility value of databases will increase if data groups constituting thestored database can freely be retrieved and subjected to informationprocessing therebetween.

Conventionally, such data have been stored in memory devices ofcomputers, and necessary information has been readout electrically andsubjected to arithmetic processing, so as to carry out informationprocessing.

DISCLOSURE OF THE INVENTION

In the case where information processing is to be carried out betweendata groups each comprising a number of data items when processinginformation of such a database, arithmetic operations are necessarybetween individual data items constituting a data group or in the wholedata group. It has been common for conventional electronic informationprocessing apparatus to carryout these arithmetic operations as occasionarises, or a number of arithmetic processing circuits are provided so asto carry out the arithmetic operations in parallel.

In the former case, even when a high-speed arithmetic processing circuitis utilized, the arithmetic processing time dramatically increases ifthe number of processing data items becomes enormous, which makes itdifficult to raise the information processing speed. On the other hand,the latter case is problematic in that the number of circuits becomesenormous, thereby raising the cost of the apparatus. Also, it isinefficient when the number of data items constituting the data groupsis small.

Therefore, in view of the problems mentioned above, it is an object ofthe present invention to provide an information processing method andinformation processing system which can efficiently carry outinformation processing between data groups each having a number of dataitems at a high speed.

For overcoming the above-mentioned problems, the information processingmethod in accordance with the present invention comprises the step ofcarrying out parallel information processing between a plurality ofinformation groups each comprising a plurality of information items;wherein a plurality of data items constituting data group informationare arranged three-dimensionally; and wherein a data correlationcalculation between a plurality of thus arranged information groups iscarried out by utilizing an arrangement characteristic.

On the other hand, the information processing system in accordance withthe present invention is an information processing system for processinginformation between a plurality of information groups each comprising aplurality of information items in parallel; the system comprisingarranging means for three-dimensionally arranging a plurality of dataitems constituting data group information into a predetermined form, andarithmetic means for carrying out a data correlation calculation betweena plurality of information groups arranged by the arranging means.

According to the present invention, a data group comprising a number ofdata items is expressed as a predetermined virtual three-dimensionalimage. The data correlation calculation can be carried out easily at ahigh speed by utilizing a characteristic of the three-dimensional image.

Preferably, each data group information is arranged as a hologram image,and an image correlation calculation is carried out between hologramimages. As a consequence, an information group comprising a plurality ofinformation items is expressed as a single hologram image. When a datacorrelation calculation is performed between the holograph images, thearithmetic operation between information groups having a large amount ofdata can be carried out efficiently at a high speed. The hologram imagemay be either projected as an optical hologram image or held in a memorywithin a computer.

Preferably, the arithmetic means projects a hologram image representingeach data group, and optically carries out an image correlationcalculation.

Carrying out an optical image correlation calculation makes itunnecessary to construct arithmetic devices by a number corresponding tothe number of pixels as in an electronic parallel arithmetic processingsystem, whereby information of data groups including a number ofinformation items can be processed effectively with a small amount ofresources without requiring enormous hardware and software resourceseven when the amount of data is very large.

Preferably, hologram image preparing means for forming a predeterminedhologram image is further provided. This is favorable in thatinformation processing of data groups becomes easier.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a first embodiment of the informationprocessing system in accordance with the present invention as a whole;

FIG. 2 is a view for explaining a hologram image representing a datagroup used in the apparatus of FIG. 1;

FIGS. 3 and 4 are views for explaining the recording and reproducing ofthe hologram image of FIG. 2; and

FIG. 5 is a diagram showing a second embodiment of the informationprocessing system in accordance with the present invention as a whole.

BEST MODES FOR CARRYING OUT THE INVENTION

In the following, preferred embodiments of the present invention will beexplained in detail with reference to the accompanying drawings. Tofacilitate the comprehension of the explanation, the same referencenumerals denote the same parts, where possible, throughout the drawings,and a repeated explanation will be omitted.

FIG. 1 is a schematic diagram of the information processing system inaccordance with the present invention. This system is one which projectshologram images 7 a, 7 b, each representing a data group, and opticallycarries out a correlation calculation between the two images; and isconfigured as will be explained in the following.

This system is roughly divided into a projection system for projectinghologram images, and an arithmetic processing system for carrying out animage correlation calculation between the projected hologram images.

First, the projection system has hologram devices 6 a, 6 b in which thehologram images 7 a, 7 b are recorded. The hologram devices 6 a, 6 b areconfigured such that laser beams split by a splitter 20 and a mirror 21after being emitted from a laser light source 1 are made incidentthereon, whereas acoustooptical cells 5 a, 5 b, each made of a singlecrystal of tellurium dioxide, for example, are arranged on therespective incident optical paths of the laser light beams. Connected tothe respective acoustooptical cells 5 a, 5 b are voltage-controlledoscillators (VCOs) 4 a, 4 b for generating a high-frequency voltage forcontrolling their operations, whereas control voltage generatingcircuits 3 a, 3 b are connected to the VCOs 4 a, 4 b, respectively.

The arithmetic processing system has a Fourier transform lens 8 intowhich the hologram images 7 a, 7 b are introduced, and a spatial lightmodulator (SLM) 9 of optical address type having a writing lightentrance surface arranged at a focal position of the lens 8, whereas ahalf mirror 10 is disposed on the reading light entrance surface side ofthe SLM 9, whereby the reading light emitted from a laser light source12 is guided to the reading light entrance surface of the SLM 9 by wayof a mirror 11 and the half mirror 10. A Fourier transform lens 13 isarranged on an extension of the path from the SLM 9 to the half mirror10, whereas a photodetector 14 is disposed at a focal position of thelens 13.

A hologram image used in this system will now be explained. FIG. 2 is aperspective view of the hologram image 7 a (the same as 7 b). Forsimplification, the case where a data group composed of 3×3×3=27 itemsof data is turned into a hologram image will be explained here by way ofexample.

As shown in FIG. 2, each data group is represented by arranging latticepoints by 3×3×3 on a space, assigning data items to the lattice pointsone by one, and displaying standardized data values as brightness,concentration, and phase (refractive index difference). In thefollowing, three planes each formed by nine lattice points will bereferred to as planes A, B, and C in succession from the left side ofthe drawing.

The recording and reproducing of the hologram images with respect to thehologram devices 6 a, 6 b will be explained with reference to FIGS. 3and 4. First, for recording a hologram image, an image of apredetermined plane, such as plane A, in a hologram image to berecorded, is displayed on an SLM 30, and thus displayed image is readout with a laser beam, so as to irradiate the hologram device 6 a. Onthe other hand, the crystal plane is irradiated with another laser beamacting as reference light by an angle of θ₁, whereby an image of theprojected plane A is recorded within the crystal. While the SLM 30 ismoved in the direction of optical axis of reading laser beam, thedisplaying image is successively switched to images of planes B and C,whereby a predetermined hologram can be recorded within the hologramdevice 6 a. Further, with the angle of reference light being changed toθ₂, similar recording may be carried out, whereby another hologram imagecan be recorded. In the case of 1 cm³ of a single crystal of lithiumniobate, about 5000 planar images can be recorded.

When reproducing the recorded information, reproducing light is madeincident on the crystal at the angle of θ₁. As a consequence, thehologram image written with the reference light at the angle of θ₁ isread out and projected.

Explanations will now be provided for operations of this system as awhole, i.e., the information processing method in accordance with thepresent invention. First, a number of data items are standardized, eachdata item is expressed by brightness, luminance, and the like, andhologram devices 6 a, 6 b each arranging the data items spatially, i.e.,three-dimensionally, so as to record them as a hologram image areprepared. Recorded in the hologram devices 6 a, 6 b are respectivehologram images 7 a, 7 b representing data groups different from eachother.

Laser light emitted from the light source 1 is split into two by thebeam splitter 20, one of thus obtained two laser beams is directlyintroduced to the acoustooptical cell 5 b, whereas the other isreflected by the mirror 21 so as to be guided to the acoustooptical cell5 a. To the respective transducers of the acoustooptical cells 5 a, 5 b,high-frequency voltages are applied from their corresponding VCOs 4 a, 4b. The frequencies of the high-frequency voltages can be changed byadjusting the control voltages applied to the VCOs 4 a, 4 b from thecontrol voltage generating circuits 3 a, 3 b. Within the acoustoopticalcells 5 a, 5 b, ultrasonic waves are propagated by the high-frequencyvoltages applied to their transducers, and thus propagating ultrasonicwaves function as gratings for the incident laser light, whereby lightis diffracted by angles corresponding to the spatial frequencies of thegratings. When the hologram devices 6 a, 6 b are thus irradiated withlaser light having a predetermined angle as reading light, predeterminedhologram images 7 a, 7 b are projected.

The read-out hologram images 7 a, 7 b are optically subjected to jointFourier transform by the Fourier transform lens 8, whereby a jointFourier transform image is formed on the writing surface of the SLM 9.The laser beam is made incident on the reading light entrance surface ofthe SLM 9 from the laser light source 12 by way of the mirror 11 andhalf mirror 10, so as to readout this image. Thus read-out image issubjected to Fourier transform again by the Fourier transform lens 13,whereby a correlation value between the object image and a referenceimage can be obtained by the photodetector 14. At that time, results ofarithmetic operations between predetermined planes of the hologramimages 7 a, 7 b are obtained when the photodetector 14 is moved in theoptical axis direction.

The high-frequency voltages applied to the acoustooptical cells 5 a, 5 bcan have a frequency of 100 MHz or higher. In this case, about 1000images can sequentially be read out per second from the hologram devices6 a, 6 b. When an SLM having a response speed of 1 millisecond is usedas the SLM 9 for arithmetic operations, a correlation calculation can becarried out by a unit of milliseconds between hologram images eachhaving 1000×1000×1000 pixels with each pixel being displayed by an 8-bit(256-gradation) grayscale.

FIG. 5 is a schematic diagram showing a second embodiment of theinformation processing system in accordance with the present invention.This apparatus has a configuration different from that of the firstembodiment shown in FIG. 1 in the projection system for hologram images.In this apparatus, hologram images are determined by a computer 43 fromcalculations according to each data item of data groups, thus determinedimages are stored in their corresponding memories 42 a, 42 b, and thusstored images are displayed in spatial light modulators 41 a, 41 b ofelectric address type, whereby the hologram images are projected.

This system can carry out a correlation calculation between images at ahigh speed as with the first embodiment. The correlation calculation mayalso be carried out between interference fringe images, on which thehologram images are based, instead of the hologram images. The accuracyin arithmetic operation is expected to improve in this case since theimages for carrying out the correlation calculation are compressed intotwo-dimensional images.

Though the foregoing explanation relates to an example carrying out anoptical correlation calculation, calculations may be carried outelectronically with data being arranged on a memory of a computer. Inthis case, with computer holograms being generated by calculations, anarithmetic operation (e.g., correlation calculation) may be carried outbetween their images, so as to reduce the amount of arithmeticoperations, thereby making it possible to perform high-speed arithmeticoperations.

The data groups may be arranged on a surface of a virtualthree-dimensional body having a predetermined characteristic ortherewithin. When a correlation calculation between three-dimensionalbodies is carried out by utilizing a characteristic of a virtualthree-dimensional body, the amount of arithmetic operations cansimilarly be reduced, whereby high-speed arithmetic operations can becarried out.

INDUSTRIAL APPLICABILITY

The present invention is widely applicable to apparatus and methodswhich analyze various kinds of data such as statistical data andfinancial data in a multifaceted fashion.

1. A method of performing parallel information processing between aplurality of information groups each comprising a plurality ofinformation items, said method comprising the steps of:three-dimensionally arranging a plurality of data items constitutingdata group information; and performing a data correlation calculationbetween a plurality of these three-dimensionally arranged informationgroups based on an arrangement characteristic thereof.
 2. An informationprocessing method according to claim 1, wherein said data groupinformation is arranged as a hologram image; and wherein an imagecorrelation calculation is carried out between hologram images.
 3. Aninformation processing system for processing information between aplurality of information groups each comprising a plurality ofinformation items in parallel, said system comprising: arranging meansfor three-dimensionally arranging a plurality of data items constitutingdata group information; and arithmetic means for performing a datacorrelation calculation between a plurality of these three-dimensionallyarranged information groups based on an arrangement characteristicthereof.
 4. An information processing system according to claim 3,wherein said arranging means arranges said data items as a predeterminedhologram image; and wherein said arithmetic means carries out an imagecorrelation calculation between a plurality of hologram images so as toperform said data correlation calculation.
 5. An information processingsystem according to claim 4, wherein said arithmetic means projects ahologram image representing each data group and optically carries outsaid image correlation calculation.
 6. An information processing systemaccording to claim 4, further comprising hologram image preparing meansfor forming said predetermined hologram image.